<s>
Stimulated	B-Algorithm
Raman	I-Algorithm
spectroscopy	I-Algorithm
,	O
also	O
referred	O
to	O
as	O
stimulated	O
Raman	O
scattering	O
(	O
SRS	O
)	O
is	O
a	O
form	O
of	O
spectroscopy	O
employed	O
in	O
physics	O
,	O
chemistry	O
,	O
biology	O
,	O
and	O
other	O
fields	O
.	O
</s>
<s>
The	O
basic	O
mechanism	O
resembles	O
that	O
of	O
spontaneous	B-Algorithm
Raman	I-Algorithm
spectroscopy	I-Algorithm
:	O
a	O
pump	O
photon	O
,	O
of	O
the	O
angular	O
frequency	O
,	O
which	O
is	O
scattered	O
by	O
a	O
molecule	O
has	O
some	O
small	O
probability	O
of	O
inducing	O
some	O
vibrational	O
(	O
or	O
rotational	O
)	O
transition	O
,	O
as	O
opposed	O
to	O
inducing	O
a	O
simple	O
Rayleigh	O
transition	O
.	O
</s>
<s>
However	O
,	O
SRS	O
,	O
as	O
opposed	O
to	O
spontaneous	B-Algorithm
Raman	I-Algorithm
spectroscopy	I-Algorithm
,	O
is	O
a	O
third-order	O
non-linear	O
phenomenon	O
involving	O
a	O
second	O
photon	O
—	O
the	O
Stokes	O
photon	O
of	O
angular	O
frequency	O
—	O
which	O
stimulates	O
a	O
specific	O
transition	O
.	O
</s>
<s>
This	O
spectral	O
fingerprint	O
differs	O
from	O
those	O
obtained	O
by	O
other	O
spectroscopy	O
methods	O
such	O
as	O
Rayleigh	O
scattering	O
as	O
the	O
Raman	B-Algorithm
transitions	I-Algorithm
confer	O
to	O
different	O
exclusion	O
rules	O
than	O
those	O
that	O
apply	O
for	O
Rayleigh	O
transitions	O
.	O
</s>
<s>
When	O
the	O
difference	O
in	O
wavelengths	O
between	O
both	O
lasers	O
is	O
close	O
to	O
some	O
Raman	B-Algorithm
transition	I-Algorithm
,	O
the	O
Raman	O
gain	O
coefficient	O
receives	O
values	O
on	O
the	O
order	O
of	O
resulting	O
with	O
an	O
efficient	O
SRS	O
.	O
</s>
<s>
As	O
this	O
difference	O
starts	O
to	O
differ	O
from	O
a	O
specific	O
Raman	B-Algorithm
transition	I-Algorithm
the	O
value	O
of	O
the	O
Raman	O
gain	O
coefficient	O
drops	O
down	O
and	O
the	O
process	O
becomes	O
increasingly	O
less	O
efficient	O
and	O
less	O
detectable	O
.	O
</s>
<s>
Furthermore	O
,	O
the	O
signal	O
intensity	O
of	O
SRS	O
is	O
also	O
several	O
orders	O
of	O
magnitude	O
higher	O
than	O
another	O
highly	O
common	O
sort	O
of	O
spectroscopy	O
–	O
coherent	B-Algorithm
anti-Stokes	I-Algorithm
Raman	I-Algorithm
spectroscopy	I-Algorithm
.	O
</s>
<s>
There	O
are	O
two	O
additional	O
prominent	O
variants	O
of	O
spontaneous	B-Algorithm
Raman	I-Algorithm
spectroscopy	I-Algorithm
–	O
surface-enhanced	B-Algorithm
Raman	I-Algorithm
spectroscopy	I-Algorithm
and	O
resonance	B-Algorithm
Raman	I-Algorithm
spectroscopy	I-Algorithm
.	O
</s>
<s>
The	O
former	O
is	O
designated	O
for	O
Raman	B-Algorithm
spectroscopy	I-Algorithm
of	O
molecules	O
adsorbed	O
on	O
rough	O
surfaces	O
such	O
as	O
metal	O
surfaces	O
or	O
nanostructures	O
where	O
it	O
magnifies	O
the	O
Raman	O
signal	O
by	O
many	O
orders	O
of	O
magnitude	O
.	O
</s>
